The leading Democratic presidential candidate joins her rivals in calling for a federal probe of Exxon's climate science research and years of denial.

Democratic presidential frontrunner Hillary Clinton voiced support Thursday for a Department of Justice investigation into whether ExxonMobil purposefully misled the American public on climate change.

When asked after a town hall event in Berlin, N.H. whether she would call for a federal probe into Exxon, Clinton replied, "Yes, yes, they should. There's a lot of evidence that they misled people."

The Clinton campaign did not respond to InsideClimate News' request for further comment.

Clinton joins a growing number of politicians—including both of her Democratic presidential challengers—calling for the Justice Department to investigate ExxonMobil for sowing doubt about climate change after the company's own scientists had confirmed and accepted the role of fossil fuels in global warming. Vermont Senator Bernie Sanders sent a letter to Attorney General Loretta Lynch earlier this month asking for a task force to investigate Exxon. Governor Martin O'Malley voiced his support for an investigation on Twitter.

Hours before Clinton's statement Thursday, four U.S. Senators, led by Sheldon Whitehouse of Rhode Island, sent a letter to ExxonMobil Corp. asking whether it made donations to a financial clearinghouse that were funneled to climate denial groups after the company said it had stopped making direct contributions to them.

The calls for investigation have been prompted by ongoing reporting from InsideClimate News, and separate but related project by the Los Angeles Times. InsideClimate News found that Exxon scientists conducted rigorous climate research from the late-1970s to mid-1980s and warned top company executives about how global warming posed a threat to Exxon's core business. The company later curtailed its research program before leading a decades-long campaign to create doubt about the scientific evidence for man-made climate change.

Environmental writer-turned-activist and 350.org co-founder Bill McKibben protested and got arrested outside an ExxonMobil gas station in Burlington, Vt. earlier this month to bring attention to the series. McKibben has also written opinion pieces in The New Yorker and The Guardian newspaper.

The politicians are requesting that the Justice Department look into whether Exxon violated the Racketeering Influenced and Corrupt Organizations (RICO) law, which federal officials used to prosecute tobacco companies in the 1990s for lying about what they knew about the health impacts of smoking.

Clinton was asked about a potential investigation by Jordan Cichon, a resident of Dover, N.H. and a community organizer for the environmental group 350 Action, after the town hall meeting. Her answer was captured on video and posted on Twitter late Thursday afternoon.

Correction: An earlier version of this article misstated the group Jordan Cichon works with. She is a community organizer for 350 Action, not 350.org.